#include        <stdio.h>

#include 		<stdlib.h>

#include        <termios.h>


#define  oops(s,x) 
{ 
perror(s); 
exit(x);
 }


int main(int argc, char *argv[])

{
        
struct termios info;

       
 if ( argc == 1 ) 
		
exit(0);

       
 if ( tcgetattr(0,&info) == -1 )          
/* 
get attribs   
*/
			
oops("tcgettattr", 1);

        
if ( argv[1][0] == 'y' )
                
info.c_lflag |= ECHO ;          
/* 
turn on bit    
*/
        
else
                
info.c_lflag &= ~ECHO ;         
/* 
turn off bit   
*/

       
 if ( tcsetattr(0,TCSANOW,&info) == -1 ) 
/* 
set attribs   
 */
               
oops("tcsetattr",2);
	
		
return 0;

}
